Three men, possibly stevedores, loading (or unloading) a large barrel on to (or off of) a freighter, sometimes around the the 1870s. The back of the photograph is inscribed "Atlantic Dock".
The photograph is by George Bradford Brainerd, 1845-1887. He was a civil engineer who worked for the city of Brooklyn as Deputy Water Purveyor from 1869 to 1886. His book The Water Works of Brooklyn: A Historical and Descriptive Account of the Construction of the Works, and the Quantity, Quality and Cost of the Supply, 1873 is still available. Even more relevant to Red Hook is his 1868 report in The American Naturalist on the sedimentary layers under the Erie Basin. In addition to this work, a focused amateur photographer, captured many images of his Brooklyn home and the natural world.